Manufacture of tools for turning, boring, and similar purposes



I w. E. KIMBER, MANUFACTURE OF TOOLS FOR TURNING, BORING, AND SIMILAR PURPOSES, APPLICATION FILED NOV-13.1918.

1359359, Patented Nov. 16, 1920.

tcrnperature (about 1800 n o r all 5.

PAil lhl l tlFFlCE.

"WALTER EDWARD KIMBEBJ. OF LONDON, ENGLAND.

lVIANUFACTURE 0F T-UULS FOR TURNING, BURING, AND SIMILAR PURPOSES.

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fication.

The invention relates to the method of producing a composite. bar for the production of tools forturning, planing boring and similar purposes and comprising a shank or stem of mild or carbon steel with a portion of high speed steel attached thereto in the position where the operative or acting edge of such tool is desired to be termed, and the essential or characteristic feature is the attachment of the two portions by a fused joint or connection through their point of contact, and which is effected with the total exclusion of air and while the high speed steel is in the necessary molten condi' tion to insure the fusion of the portion of the carbon tool steel with which it is brought into contact.

A comparatively small portion oi the shank only is required to receive the high speed steel and it is this portion which is introduced into a pocket of refractory material which can be handled and manipulated so as to insure the required conditions being fulfilled, and which is secured by the previous insertion of the shank of carbon steel into the rciractor T pocket and the immersion of same into a bath of molten high speed steel to allow the latter to enter the pocket through an opening therein when it is plunged or immersed below the surface. The shank is protector against total fusion during immersion in the molten high speed steel by the refractory pocket and said molten-metal is permitted to come in contact with a small edge or area only of the shank. The molten high speed steel is of so high a C.) that the immersion therein. of an unprotected shank ct mild steel .would. cause the immediate fusion and disappearance of said shamh into the mass of molten metal.

The method is not a ca ting process. but essentially a fusing procc y imn'wrsion.

liy the immersion of the whole pocket in molten metal all access of air is entirely prevented and consequent oxidation rendered Specification of Letters Patent.

Patented Nov. iifi, 1920.-

Applicatioh filed November 13, 1918. Serial No. 262,347.

impossible, and the placing of the pocket with the contained portion of shank together underthe steel, the molten metal outside the pocket allows the molten metal inside the pocket to remain in a molten condition for as long as is required to efl ect perfect fusion, and as a fact if allowed to remain for too long a period. the whole thing-win. the shank inclusive would be reduced to a molten condition.

The exposure of a small portion of high speed steel in a molten condition to the atmosphere entirely deteriorates same by oxidation so as to render it useless.

The immersion of the shank when in the pocket into molten steel and its removal in such pocket therefrom with the small portion of high speed steel attached thereto entirely prevents all possibility of access of air to the portion during the whole operation of its attachment.

in the accompanying drawing illustrating the manner oi' carrying my invention into effect- F igure 1 is a vertical section through the pocket of highly refractory material employed toreceive the portion of the body or stem to which the high speed steel is to be applied.

F 2 a plan view tion.

Fig. 3 an elevation oi the lower end of the body or stem after removal from the pocket and as indicated by the shade or section lines with the applied portion of high speed steel shaped to the desired term.

Fig. 4 is a vertical section of the lower. portion oi? the pocket shown in Fig. 1 provided with an opening near the bottom thereof, through which molten. steel may enter.

For the purpose of this invention a length of mild steel preferably of rectangular section and of a suitable length and shape is employed to approximately constitute the body or stem 1 but with a portion 2 omitted or removed Where the cutting or operative edge of the tool is required to be'formed, and which extends back along such body or a sufhcient distance to attord an effective bearing surface for the welded joint with the portion of the high speed steel 3 it is intended to receive.

The body or stem 1 so shaped is introduced into a pocket 4 of highly refractory material such as Sheffield clay as used for thereof or partly in secsteel melting crucibles, and the interior of which is'shaped so that when the stem 1 bears on the bottom thereof with the enlarged portion inserted within the mouth of the pocket, a clear space 5 will be left opposite the removed portion oi the stem.

The opening in the pocket 1 is at the bot tom recessed or reduced at 6 to receive the end of the reduced portion of the stem 1 which is inserted therein, so as to hold the stem in position within the pocket with the clear space 5 of uniform depth throughout its length on that side to which the high speed steel 3 is to be applied.

An opening 7 through the wall or the pocket at opposite such space 5 communicates with the interior at a point near the top thereof, and such wall is, as shown, advantageousl made thinner 'than the remaining wa ls or sides of the pocket.

After the stein 1 has been introduced a wedge 8 of refractory material is inserted in the mouth of the pocket 4 to fix same therein and close the clearance which exists between it and the wall on one side, while the other sides may if necessary be sealed with refractory clay.

The pocket at with the stem 1 inserted therein is preheated to a bright red heat and then plunged into a pot of molten high s eed steel (to the level indicated at 9 .in h ig. 1) until the hole 7 near the top of the pocket is submerged, which allows such high speed steel to pass to the interior and fill the space 5 left where the-removed portion 2 of the stem 1 is situated- The pocket d is allowed to remain submerged for a sufficient length of tin1e"-(about minute or two) to enable the entering high speed steel 3 to act upon the surface of the stem 1 to which it is required to unite to bring same to and maintain it at a fusing heat, the decreased thickness of the wall through which the molten steel enters in comparison to/that of the other walls of the pocket, assisting this action by the greater radiation of heat Y through same from the outer molten steel in the pot in which the pocliet is submerged.

An opening 10 indicated in dotted lines in Fig. 1, may also be provided near the bottom of the pocket 4i so that the molten steel may pass to the space in the interior at both bottom and top, and to prevent the metal running back as the pocket is withdrawn such bottom opening 10 might be first closed by refractory clay forced down on the end or a rod, hetorc the removal of the pocket from the pot is effected. This opening 10 may be omitted.

After the necessary immersion the pocket l is withdrawn from the pot with the stem 1 it contains and the high speed steel which has entered same, and is immediately plunged into or covered with refractory material, such as sand, to prevent the possibilinsane-e ity of access of air, and allowed to remain until sufliciently cool to permit of the removal oi the pocket, which may be broken off leaving the stem 1 with the portion of high speed steel 3 securelyattached thereto by fusion at the position 2 reserved for its reception.

The inclosing of the portion of the stem 1 which to receive the high speed steel within the pocket 4- during the fusing or joining of such high speed steel thereto, by excluding all access of air insures the formation of an eflicicnt joint, all risk or: oxidation of-the high speed steel being effectually prevented.

The space provided in the pocket t is preferably such as will insure an excess of attached high speed steel on the stem 1 to that required to fill the space 2 reserved. therefor, which excess will as illustrated in Fig. allow forthe forging or shaping necessary of the combined or composite bar oi. mild steel and high speed to the required .torm to present the necessary cut ting or operative surface at the desired point. p

The high speed steel migl'it be melted in the pocket 4t itself and the stem 1 after preheating be plunged into the molten metal. and "the whole allowed to remain until the desired fusion is effected, when the pocket 4i with the stem 1. therein would be removed "from the. furnace in which it had been bar of mild and high speed steel for forrnation of tools for turnin and lilre or moses to L i which consists in firing in a refractory apertured pocket a stern of mild steel with a portion of its surface spaced from the wall of said pocket, immersing said pocket and.

contained stem. in a molten bath oi high speed steel and subjecting the said protected stem bodily to the indirect heat oi said bath and along the spaced portion thereof simultaneously to direct contact of the inflow of molten bath high speed steel until said spaced surface is brought to a fusing heat and united with the metal of said inflow, and then withdrawing said pocket and contents from. said bath.

2. The method oi producing a composite bar of; mild and high speed steel :t'or tormetion of tools for turning and like purposes which consists in fixing in a refractory erturcd pocket a stem of mild steel with a portion oi? its surface spaced irom the wall said bath and along the spaced portion thereof simultaneously to direct contactof the inflow of molten bath high speed steel until said spaced surface is brought to a fusing heat and united with the metal of said inflow, and then withdrawing said pocket and contents from said bath.

3. The-method of producing a composite bar of mild and high speed steel for formation of tools for turning and like purposes which consists in forming a stem of mild steel or carbon tool steel with a recess through a portion of its length, fixing in a refractory apertured pocket said stem of mild steel with the recessed portion of its surface spaced from the wall of said pocket, immersing said pocket and contained stem in a molten bath of high speed steel and subjecting the said protected stem bodily to the indirect heat of'said bath and along the 20 spaced portion thereof simultaneously to di-' rect contact of the inflow of molten bath high speed steel until said spaced surface is brought to a fusing heat and united with the metal of said inflow, and then Withdrawing 25 said pocket and contents from said bath.

In testimony whereof I have signed'my name to this specification in the presence of two subscribing witnesses.

WALTER EDWARD KIMBER.

WVitnesses:

LAWRENCE G. LEE, WILLIAM JAs. FERRY. 

